Field of the Invention
The present invention relates to a conversion technique of a document format.
Description of the Related Art
Conventionally, a technique to convert a document format by making use of a printer driver is known. For example, there is a printer driver (hereinafter, “PDF conversion driver”) that converts document data in an arbitrary format into document data in the PDF (Portable Document Format) format. It is possible for the PDF conversion driver to produce an output as PDF data by performing the same operation as that of printing in an application of business form creation or document management.
In the printing system of Windows (registered trademark) OS of Microsoft Corporation, as the graphics engine, the GDI (Graphics Driver Interface) is used. The conventional printing processing flow using the GDI is called a GDI print path. In the GDI print path, a drawing command in the GDI type issued by an application calling a service function group of the GDI is converted into PDL data by a Version 3 printer driver (hereinafter, “V3 driver”) and output to a printing apparatus. PDL data is data described in a page description language that can be interpreted by a printing apparatus. Then, after Windows 8 (registered trademark), a new printing processing flow called an XPS print path is added thereto. The XPS is an XML-based electronic document format and XPS is an abbreviation of XML Paper Specification. In the XPS print path, drawing data in the XPS type is generated in an application and the drawing data is converted into PDL data by a Version 4 printer driver (hereinafter, “V4 driver”) and output to a printing apparatus.
The GDI print path and the XPS print path are not in an exclusive relationship and for example, it is possible to convert drawing data in the GDI type generated by an application using the GDI into the XPS type and to convert the drawing data into PDL data by the V4 driver. At this time, conversion from the GDI type into the XPS type is performed by a conversion module called an MXDC (Microsoft XPS Document Converter).
In conversion from the GDI type into the XPS type by the MXDC, there is a case where a text object is replaced with a path object or an image object Here, a text object refers to an object with a text attribute specified by font information and character code. A path object refers to an object with a path attribute specified by path coordinate values and a drawing method and an image object refers to an object with an image attribute specified by size and color information on each pixel. A text object being replaced with a path object or an image object (hereinafter, a non-text object) means that the drawing contents specified with the text attribute on the side of an application are transmitted to the V4 driver as drawing with the path (graphics) attribute or the image attribute. Such replacement may occur in the case where the font that is used for drawing of a text object is an embedding-prohibited font whose embedding into an electronic document is prohibited. In the XPS type, embedding of a font is specified as the format thereof, but it is not possible to embed an embedding-prohibited font. Because of this, a text object that uses an embedding-prohibited font is converted into a path object or an image object. It is known that such replacement of the object attribute, which is not intended by a user, occurs also in the case where decoration, such as transmittance, is specified for a text object.
Then, in the case where the above-described replacement occurs at the time of generation of PDF data by, for example, a PDF conversion driver, which is the V4 driver, such a problem arises that it is no longer possible to search the portion as text and image quality deteriorates.
Consequently, an object of the present invention is to prevent the above-described problem from arising even in the case where the object attribute is changed from the text attribute to the non-text attribute by the MXDC. Specifically, it is made possible for the V4 driver to generate PDL data (or PDF data) that gives instructions to draw the object portion whose attribute is originally the text attribute in drawing data in the XPS type after conversion, which is generated by the MXDC, with the text attribute.